[Insight-users] ContourExtractor2DImageFilter producing closed paths for line segments

[David Doria]

In this example:
http://www.itk.org/Wiki/ITK/Examples/Segmentation/ContourExtractor2DImageFilter

I create an image of two simple line segments (values of 255 on an
otherwise 0 background). Then I extract them as contours using
ContourExtractor2DImageFilter. As it says in the documentation, this
filter generate closed paths. That is, I create a line like this:

  // Create another line of pixels
  for(unsigned int i = 10; i < 20; ++i)
    {
    itk::Index<2> pixel;
    pixel[0] = 10;
    pixel[1] = i;
    image->SetPixel(pixel, 255);
    }

and the path it returns is

[10.502, 19] // one end point
[10.4624, 18]
[10.4624, 17]
[10.4624, 16]
[10.4624, 15]
[10.4624, 14]
[10.4624, 13]
[10.4624, 12]
[10.4624, 11]
[10.502, 10] // the other end point! (how to detect this?)
[10, 9.58388]
[9.49804, 10]
[9.53758, 11]
[9.53758, 12]
[9.53758, 13]
[9.53758, 14]
[9.53758, 15]
[9.53758, 16]
[9.53758, 17]
[9.53758, 18]
[9.49804, 19]
[10, 19.4161]
[10.502, 19]

rather than just

[10.502, 19] // one end point
[10.4624, 18]
[10.4624, 17]
[10.4624, 16]
[10.4624, 15]
[10.4624, 14]
[10.4624, 13]
[10.4624, 12]
[10.4624, 11]
[10.502, 10]
[10, 9.58388] // the other end point

like I would like.

Is there any way to identify the endpoints of the contours produced by
this filter if the image indeed contains open contours like these line
segments?

Thanks,

David